p class=”note”>I have been struggling with the question of whether to keep writing on science issues, particularly since it’s not my area of expertise (even though I’m very fond of thinking about these issues). I’ve decided to compromise and try to write about science and research policies and projects, which are of interest to the entire ASD community, separate from discussions about what any given study “means.” Let me know your thoughts.
This brief summary of a discovery relating to the genetic basis of a tremendous difference in treatment efficacy for Hepatitis C across broad groups of people is a great example of the promise of genetics.
Using these sorts of genome-wide association studies, geneticists can discover distinctions that are hard to find otherwise. In this case, they observed different effectiveness of treatment protocols that seemed correlated with racial groups. Beyond the almost-paralyzing aspects of prescribing by race, of treating patients differently because of something so seemingly unrelated as skin color, these researchers prevailed by in fact ignoring race and treating their study subjects as simply people. By comparing them at the level of DNA, they discerned that a single base pair, a T or C (thymine or cytosine) in one single location out of over 3 billion, explained much of the difference in treatment outcomes. These results almost certainly are better predictors of outcome than “race.” They correlate with race to some extent, but not completely, because “races” have historically been tightly correlated with geography, and genes can only spread at the rate of the humans who carry and transfer them.
Will these techniques work for ASD? The answer is almost certainly yes, and studies of this type are being conducted and results published. The difficult factors are the apparent fact that many genes are involved in ASD, as opposed to a single gene-type disease such as sickle cell anemia (which is a single-base pair disease) or cystic fibrosis (which is a single-gene disease); also, the fuzzy nature of ASDs makes it very hard for researchers to know what expression of the disease they should be matching to which set of genes. The Simons Simplex Collection page is addressing this problem when it refers to “rigorous phenotyping.” These aren’t unsolvable problems, but they’re hard.
I will look at the underlying paper to report on the scale of the research, which is important as we consider the value, need, and continued support of genetics resources collected by the AGRE/the Simons Simplex Collection to study ASD genetics. My goal in reviewing this paper will be to collect information on the number of people they tested against what number of criteria.
It’s possible that we can, as we identify the “resolution power” of these types of studies, determine how many people’s DNA we need, based on the number of ASD categories we are testing and the error rate of assigning them to appropriate categories. Certainly other people are more qualified to explore these issues and do the calculations, but those numbers should be communicated to parents of children with autism and individuals with autism so that they can understand how important it is for them to participate in such studies.
Do you have questions about how genetics research works? Or what studies measure which things? Ask your questions in the comments.